The congenital color vision disorder is generally called colorblindness, which can not distinguish various colors or certain color(s) in the natural spectrum. The colorblindness is divided into total colorblindness and partial colorblindness (red colorblindness, green colorblindness, blue-yellow colorblindness, etc.). The total colorblindness belongs to complete cone cell dysfunction, and it is the most severe color vision disorder. The red colorblindness and the green colorblindness in the partial colorblindness are called red-green colorblindness.
The red-green colorblindness brings about a lot of inconvenience to a patient himself/herself, for example, it is not easy for him to identify traffic lights and other signs, he is deprived of qualifications of occupations that require sensitive color vision, the patient's perception of the colorful world will be affected, and yet such a congenital deficiency can not be healed in posteriority. Nowadays, there still lacks a system which may more effectively assist a colorblind user in normal identification.